Boron isotopic composition and concentration of ten geological reference materials

We present boron isotope and concentration data from magmatic (komatiitic to rhyolitic) and sedimentary geological silicate and artificial glass reference materials that cover a wide spectrum of boron isotope compositions and boron concentrations. Boron isotope compositions were determined by TIMS (Cs2BO2+-graphite and BO2- method) and boron concentrations by ICP-AES. Boron concentrations ranged from 7 to 159 mu g g(-1) and agree within 14% with published values. Based on replicate analyses of individually prepared sample aliquots an overall external reproducibility of better than 10% was determined. The obtained delta B-11 values ranged from -12.6 to + 13.6 parts per thousand and were reproducible within 1.1 parts per thousand (2 RSD; excluding NTIMS) on the basis of individually prepared sample aliquots. The delta B-11 values of JA-1 (+5.3 parts per thousand), JB-3 (+5.9 parts per thousand) and JR-2 (+2.9 parts per thousand) overlap the published data within analytical uncertainty. For the first time delta B-11 values for the TB (-12.6 parts per thousand) and the MPI-DING glasses GOR-128-G (+13.6 parts per thousand), GOR-132-G (+7.1 parts per thousand) and StHs6/80-G (-4.5 parts per thousand) are reported. The delta B-11 values obtained by the Cs2BO2+-graphite and the BO2- method as well as the majority of delta B-11 values obtained using different sample preparation methods agree within analytical uncertainty. Therefore, we conclude that none of these analytical methods introduce any systematic error on the obtained delta B-11 values.